Red Eléctrica esclude che il blackout in Spagna e Portogallo era dovuto a un attacco informatico

The issue is still under investigation, but experts say that the massive outage was likely caused by the grid not being sufficient to handle so much energy generated by renewables. Renewables are expanding at a much higher pace than the expansion of the capacity of the electric network to handle it. So you could say we are a victim of our own success. There are plans to expand the capacity of the grid in 2026, so in the meantime either more blackouts could happen or we will have to disconnect some renewables or other power generators. We need more investments in electrical infrastructure and energy storage capacity.

I’m not sure whether I should regard that as good news anyway?

I know this has been a bit of a concern here in Ireland — we’re a literal energy island. There are no synchronous connections to any larger grid. We have interconnection but it’s DC and not all that huge a capacity. (3 x 500MW DC between Ireland and Britain) and a soon to be completed Ireland-France link at 700MW DC)

To keep a grid stable at 50Hz traditionally relies on very large spinning generators providing huge momentum — these are the generators in thermal and hydropower stations. They’re huge drivers of stability as they’re constantly outputting a steady synchronised 50Hz sine wave driven by the huge kinetic energy. Anything out of sync isn’t able to destabilise that very easily.

In a grid full of solar and wind, you’ve lots of smaller sources generating their sync largely through solid state electronics to get the 50Hz sine wave. They’re not big spinning loads like a huge generator.

More and more of our input is wind and micro generators generators.

We also have very few big consumers using rotating loads that you might find in say mining industries and concrete etc — lots of heavy AC motors actually helps. Our single biggest consumers are data centres, then households and the industry types here are all light stuff — pharma etc.

To overcome this in our grid we’ve been adding synchronous condensers (or synchronous compensators) which are just basically motor-generators spinning enormous flywheels weighting about 110 tons each. They run in low friction environments — sealed in partial vacuums, various ultra low friction bearings etc to minimise loss, but basically the idea (which has been around a long time) is that these compensate for the lack of spinning generators and stablise the otherwise isolated grid.

Generally on the continent in very large wind dependency like say Denmark, this can be done by just being in AC sync though high capacity interconnection to say Germany or to Norwegian hydro power etc, whereas Ireland has no such AC connections.

You see similar setups in places like Western Australia etc which are also isolated just by distance rather than sea.

To me it looks like the Spanish grid might have just momentarily gone out of sync and the frequency went chaotic so effectively the 15GW that went missing would have just cancelled itself out with clashing waves. Then the systems trip. Then it cascaded as one system starts tripping and then others trip and next everything goes dark. Then you have to try and identify the fault and so a “black start” (restart the grid from off) which is *very* difficult

The sun is currently experiencing a solar maximum, might it have been due to a geomagnetic storm?

The main hypothesis right now that the most likely cause was over relying on solar energy, when it is such a volatile energy source.

Maybe due a overload of the grid, because of cheap electricity prices there was a huge supply of energy to Portugal from Spain. Heat might also contributed to the problem.

Back in 2003 there was a huge black out in Ohio that also affected other US and Canadian States, there were many contributing factors and in the end a simple tree branch triggered the [black out](https://practical.engineering/blog/2022/2/9/what-really-happened-during-the-2003-blackout).

Portugal, in 2017, had a catastrophic fire in Pedrógão Grande due [abnormal weather conditions](https://www.nature.com/articles/s41598-019-50281-2) that eventually [triggered electrical discharges](https://algarvedailynews.com/news/13443-pedrogao-grande-fire-was-started-by-an-electrical-discharge-concludes-report) and started the fire. So it’s possible that something similiar also contributed to this black out.

People should be ready to a similar conclusion: multiple factors combined.